Calling all Mac owners: Let’s test the gray color flicker

AshX

Hi guys!

Just wanted to update you all that I have received my Carson Microflip and also purchased the Dell S2722DC 27” monitor. All the research I found points to it being true 8-bit, so fingers crossed.

I want to apologize for the delay in doing testing. My health has deteriorated quite quickly the past few weeks and I’ve been in and out of the emergency room and doctors offices. I was having difficulty walking and speaking so needless to say, it’s been a challenge.

I did try to use the Carson Microflip on my 2022 M2 13” Touchbar MBP. Just opening the screen even with Stillcolor enabled triggered symptoms and I wasn’t looking directly at the device very much at all. I’m going to see if my mom can test it on Monday. I’m writing this with the same focusing symptoms as a month ago. Very discouraging. I was able to take a not so great video I’ll link below. It’s hard to keep it still. If any of you have any advice of how to test properly and any eye precautions to minimize symptoms, please let me know. I hope to test the monitor next week too if I’m feeling better.

Video link: https://streamable.com/pwbo16

DisplaysShouldNotBeTVs

AshX

fyi, i remember your m2 touchbar mbp panel id started with "F0Y"

note that the only touchbar mbps with "decent panels" have been known to specifically start with "DCN" (in addition to the zeroes)

as in, all of the users here who have had at least "decent" experiences with the touchbar mbp, who posted their panel id, started with DCN

so, even though your panel id has zeroes, the F0Y implies you very likely still have a different panel manufacturer than the "better ones"

in fact, the symptoms you describe, with strong immediate strain/nausea even with stillcolor, -AND- residual issues with focusing, line up EXACTLY with the "FMX" touchbar macbook pro i tried in april 2024

on the other hand, the "DCN" one i tried back then was significantly better (but dont expect perfect. the good thing about the DCN panel though is that it didnt have any immediate strain though, and didn't cause any focusing issues IRL)

AshX

DisplaysShouldNotBeTVs

Uh oh…that would be quite unfortunate since I’m about a week out of the 30-day return window. The serial number indeed does start with F0Y:

<"FOY2441009DNTJFA4+000000004L21B4+PROD+0+0000000000000000+PA15N0803PA22N0912+6755DKG2K5002217TTTYYW1EB01424334+S68968949TS68968949TS68968949TS6896894">

The other interesting thing I noticed was the 2 stickers on the back. One says 2022 and the other says 2024. This was bought new from a reputable computer store. Here’s the link to the photo: https://imgur.com/a/SPUhpHw

So I don’t know if Apple was still making these in 2024 or at least still packaging them and if that’s playing a role with the F0Y panel. I recall you saying the FMX panel looked “better” at first glance because it was sharper and more uniform, but ultimately much more uncomfortable.

With dithering enabled I can feel my heart rate increase and as soon as I disable it, it calms down. I only get those symptoms when exposed to strobe lights and back LED lights in stores. It’s not as bad as the MacBook Air M4’s where Stillcolor made 0 difference. But I have Stillcolor set to open on startup and it made 0 difference today.

The fact that I wasn’t even looking intensely at the screen but just being exposed to the screen itself while trying to use the microscope against it for 30 second intervals was enough over the course of 10 minutes to cause eye focusing issues is absolutely insane to me.

I waited a few hours and opened the 2015 15” MBP I have that has the gray color flicker and there was no nervous system engagement at all on it. If I used it for 15 minutes, then yeah, there would be a problem. But it’s completely different than my experience with the Apple Silicon Macs. I also don’t get any of the same nervous system issues with my mom’s Dell Latitude work laptop.

Not sure what my options are with this 13” MBP is at this point if the lack of a DCN screen is what is going to make the difference. I don’t want to keep torturing myself with it if it’s a lost cause. I’d like to know why this is happening. There has to be a technical reason for this. Is it that the F0Y panel has built-in FRC and the DCN panels do not?

AshX

DisplaysShouldNotBeTVs

Went back through the Stillcolor thread and it looks like my panel is the “Tinted Panel” you and others mentioned that was acceptable. Out of the box I found it perfectly uniform and when brightness is lowered, the screen indeed does look less bright, unlike the MacBook Airs. So I don’t believe it is severe like the FMX panels.

There is only so much variance that can occur with a panel like this. Unless DCN panels are using wildly different components, I don’t quite understand what is the differentiating factor. But I’m trying to figure it out.

Is there any evidence that FRC is not being utilized on DCN panels and that is why they’re more comfortable? Is there any information as to whether this is configured on the hardware level?
Pixel behavior differences between panels (impossible to determine without microscopic comparisons of multiple panels)
Calibration and color differences (gamma, etc.)

The focusing symptoms seem to be a red flag for PWM or dithering (likely the latter). The nervous system engagement also tells me there is flickering occurring. PWM is ruled out above a certain brightness on these models so that leaves FRC assuming Stillcolor is disabling GPU dithering, which it appears to be.

Does anyone here have a DCN model who would be willing to compare under microscope pixel behavior?

DisplaysShouldNotBeTVs

AshX but just being exposed to the screen itself while trying to use the microscope against it for 30 second intervals was enough over the course of 10 minutes to cause eye focusing issues

yeah this is exactly what happened with my FMX touch bar M2. Didn't happen at all with the DCN i tested though

also, yeah, your panel is different from the DCN, because the DCN is NOT uniform

(i think you misread that thread because it's the bad panels that are uniform. the better ones seem to not be as uniform)

sell your F0Y MBP. no use in trying to make it work, sounds like bad hardware to me. M2 touch bars in like-new condition seem to still be selling for a good amount on eBay

don't expect perfection with the DCN either, although unlike the FMX and F0Y, it should at least be better enough to not cause those focusing issues and not cause immediate discomfort

DCN is the last one you should test. if DCN M2 touch bar pro works, great!

(if it doesn't, it's time to seriously consider switching to PC, or at least a comfortable PC + NoMachine connection into a Mac to view e.g. Logic Pro on the PC's screen)

AshX

DisplaysShouldNotBeTVs

So basically the only options are:

A. Buy used and ask the seller to run the terminal command and also try to find one still on MacOS Ventura.

B. Keep buying from the same supplier and hope one of them is a DCN.

I don’t think I read the thread incorrectly. There were 3 panels mentioned: FMX (bad), F0Y (Tinted Panel so long as it had the long string of zeroes it didn’t seem to trigger systemic issues), and DCN which seemed like over time to work for people more than the others. Regardless, it is clearly causing issues so that’s all there is to it.

Mostly I want to know why this is happening. It can’t just be because it’s a “bad panel.” I’m still going to try the device connected to the Dell S2722DC which I confirmed with Dell is true 8-bit unlike the 4K panel. Worse case I’ll just give the laptop to my mom rather than sell it. It’s still Apple Care eligible at this point, too.

AshX

Further update:

Dell S2722DC did not work out. Just as bad with multiple devices.

Also sold the M2 13” Touchbar Pro. Tried to take a few videos (did the best I could) under microscope. Here’s Video 1 and Video 2. At first I thought it was just my camera focusing but the Blue pixel seems to be pulsing in video 1, and maybe red and blue alternating pulsing in video 2. Hard to tell. Curious on your thoughts @DisplaysShouldNotBeTVs

Going to attempt to find a DCN panel and then I think I’m out of options.

Apologies to everyone in this thread. I’ve been doing my best to narrow down forms of flicker on these Macs, but this is certainly taking a toll financially, physically, and emotionally.

Donux

I would personally suggest to everyone, do not waste money on newish devices, especially if you already had a couple and it did not workout for you. Better get used new macbook or pc, this way you are reducing risk and also open up for various posibilities to inquire seller about hardware components. I bought macbook 2015 15 inch in mint condition, litteraly like new in the original box, with glossy screen, nothing is pealing off, nothing is overheating, everything works. Body is like a tank, totally different grade of aluminum in comparison to current batches. Batery is more than suffecient for my needs, even if usually I am plugging in everywhere I go. And damage to my bank account was minimal. I can use it all day, it is still strainy, but not clinical and adaptable too. I do not feel ungrounded with it as with M2 Air. Not to mention I was able to reclain some old software I had licences for, like paralells etc, which still work well. But at the same time, I would probably risk getting M4 Macbook Pro, I think PROs are just better with few exceptions. So for some of us, Pro might be a solution. For others, even Pro, would be too severe. Then the next bet I would put premium laptops such as used dell xps and used thinkpad premium such as thinkpads X1. All of this will cost you peanuts, in comparison to low or mid range new consumer grade laptops.

AshX

Donux M4 Macbook Pro, I think PROs are just better with few exceptions. So for some of us, Pro might be a solution. For others, even Pro, would be too severe.

My mom was gifted a 2015 15” Pro base model. It’s in rough shape - battery barely holds a charge, edges peeling off. It’s on Catalina. It’s definitely the most tolerable in terms of looking at the screen and not feeling an immediate issue. But it does have the gray color flicker and within 5-10 minutes I start feeling spaced out. That’s why I was pursuing the M1/M2 13” Pros because they seem to be the only ones that don’t have the gray color flicker or lower PWM. But despite that there is an immediate reaction to the screen - it seemed OK at first but then after two days severe symptoms of eye focusing problems.

I haven’t personally tried the new M4 MacBook Pros other than in a store. They made me dizzy but this one particular nanotexture model an Apple employee was using seemed actually usable. I know some people here have had success with them without even installing Stillcolor. I’ve thought about maybe giving a 14” a try because I used a M1 14” Pro and I actually really liked it years ago. But my health is very different now. The other issue with buying used is most people tend to upgrade the OS to the latest version. And it’s not easy to find the installers and do a DFU downgrade for the firmware if you want to bring an M2 back to Monterey or Ventura. Super complicated, super annoying, and relatively expensive.

I’m the rare one here who actually ended up in the ER in June after using the M2 Touchbar Pro because they thought I had a stroke. Couldn’t focus my eyes or move my left leg and had trouble talking. The only commonality was the laptop seemed to trigger a neuromuscular reaction that I only get under badly flickering LED or fluorescent lighting. Yet I use an iPhone 13 OLED and everything is good. I don’t understand it.

AshX

So, I have a new theory. I just tested the 2015 15” MacBook Pro under microscope. The first test was done on a blank Safari tab, approximately 60% brightness. You can watch one of the videos Here.

For the next test I used the stock Apple light gray wallpaper. Immediately it was apparent how dark the pixels looked under microscope. I boosted the brightness to 100% and it looked like this.

I actually edited the original video I posted to boost the brightness and saturation so the pixels were more visible. You can watch them all in this thread.

What if many of the panels Apple are using have trouble maintaining an even brightness level on specific colors? And what if the need for dithering (FRC on the panel perhaps) results in a dip in panel brightness and to mitigate that Apple uses PWM or some type of strobe flicker to regulate the brightness in some way?

Is there any basis for this? Or is this panel just damaged? Can someone else do testing on similar devices to determine if they see the same thing? I didn’t notice this on the iPhone 5 that was dithering on gray - the pixels were of equal brightness across images.

idontknowwho

The problem of screen flickering on Gray backgrounds is usually caused by "Pixel walk" or "Pixel inversion", that's a result of mis-adjusment of display voltage, it's a hardware issue. Here's a test to see how badly your display is affected:

http://www.lagom.nl/lcd-test/inversion.php

"Good" displays might flicker very lightly on one or two boxes. But if the flicker is strong, that means the display has bad voltage adjustment, probably because of bad Quality Control.

And it's not a new problem in macbooks, I first found out about this problem 10 years ago, when I bought a new macbook air 13" early 2015 model, its screen flickers on gray backrounds and it flickers strongly on box 3 from the test. You can find people on forums complaining about this issue since 2010 ! apparently it's common in macbooks, I'm very surprised to see that people still have this issue in 2025!!!

Here are some other reports from macbook users reporting this issue from 2010-2015 :

http://www.justinfx.com/2011/12/05/apple-macbooks-and-unexplainable-lcd-flicker/
http://apple.stackexchange.com/ques...l-walk-screen-test-truly-indicate-a-problem-o
http://hintsforums.macworld.com/showthread.php?t=115301
https://forums.macrumors.com/threads/1162962/
https://forums.macrumors.com/threads/1388740/
https://discussions.apple.com/thread/2645516?start=0&tstart=0
https://discussions.apple.com/thread/3089024
https://forums.macrumors.com/threads/1139928/

AshX

idontknowwho

Very interesting! It seems though that the flicker found on those earlier MacBooks was visible to the naked eye? Am I correct in interpreting those posts that way? Or is that just on the extreme side of the scale? I can only detect the gray color flicker on 2015-2025 Macs with 240 or even 120 fps slow motion.

The voltage issues you’re describing tracks with what the mod of the PWM sensitive and Temporal noise subreddits believed as well when I asked him about the gray color flicker, specifically he thought transistor leakage was a major contributor along with an improper voltage being sent to the display. He also said It was a hardware issue. Very interesting to see you describe the exact thing.

I’m curious if you think the new Liquid Retina panels could have exacerbated this issue. Other users have found this flicker on the iPad Airs, too. So I wonder if the more low powered + long battery life Apple devices are more prone to this. But I found the same flicker on an 2015 15” MBP and a 2019 iMac 21.5” 4K Retina. The only other theory I had was it was also a consequence of pushing very high quality graphics and resolutions on panels and hardware that couldn’t necessarily pull it off on base specs without some Apple magic under the hood. Also curious what the frequency of this flicker is as it seems fairly consistent across devices.

idontknowwho

AshX

Yes, it is visible to the naked eye (not easily though), at least in my macbook it is visible on gray backgrounds and some other dark colors. Especially if the brightness is at maximum.

Yesterday I did more research on the topic and found some new information, now I'm thinking maybe software aspect also contributes to this problem. The software issue, as you mentioned, is that gpu forces more colors on the display than it is naturally capable of producing, which is called dithering. I didn't know what dithering exactly is but now I see how it is basically just flickering between two colors to give the illusion of a color between the two.

For example my 2015 macbook air, has a 6-bit panel (6-bit for each channel), but system report in macOS says that it's doing 8-bit for each channel, that means macOS is forcing each of the R/G/B channels on the display to produce 4 times more colors than the they are naturally capable of producing (2 bits means 2² which equals 4), I guess it does this by separating it's 60hz refresh rate, into two 30hz sections, and flickering back and forth between them whenever it wants to show a color that it naturally can't. If that color is very far from the "Original/Natural" colors of lcd, the flickering will be more noticeable to the eye.

However, this dithering technique seem to exist in all macbooks (apparently silicon macs can easily disable dithering using apps like stillcolor or betterdisplay) . Some macs (like mine) show more noticeable flickering to eyes, and some users have reported that the flickering issue was resolved or greatly reduced after they replaced their macbook, which gets me to the conclusion that a hardware problem can be the main culprit, at least in more severe cases.

Battery life or low power consumption shouldn't be causing the issue, it's more about quality control I think. Sometimes it's a lottery, two exactly same devices may show different flickering severity, I remember old intel-macs had either LG or Samsung LCD panel, and It was believed that LG is more prone to flickering, so if you were lucky you would get a mac with Samsung panel.

So I guess these things will help users experience less flicker:

Using brands and models that have better reputation and quality standards.
Using displays that have more color depth on the hardware level (more bits) without any FRC/Dithering/Fake Extra color depth.
Using displays with higher refresh rate.

EDIT: DISABLING DITHERING REDUCED THE FLICKER ON MY MAC DRAMATICALLY, I WROTE A TUTORIAL ON HOW TO DO IT, IT'S VERY EASY:

https://ledstrain.org/d/3748-simple-tutorial-for-disabling-dithering-on-intel-macbook-air-maybe-other-macs

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